Conventionally, a method for installing a sound emission and collection apparatus every point at which an audio conference is conducted and connecting these apparatuses by a network and communicating a sound signal has often been used as a method for conducting an audio conference between remote places. Then, there are many apparatuses in which a loudspeaker for emitting a sound of a mate apparatus side and a microphone for collecting a sound of own apparatus side are simultaneously installed in one cabinet in the sound emission and collection apparatus.
For example, in an audio conferencing apparatus (a sound emission and collection apparatus) of Patent Reference 1, a sound signal input through a network is emitted from a loudspeaker placed in a ceiling surface and a sound signal of each microphone placed in side surfaces using plural different directions as respective front directions is collected and a sound collection signal is sent to the outside through the network.    Patent Reference 1: JP-A-8-298696